Progress report on 21-cm observations at low latitude between longitudes (l 11) 0° and 66°

1967 ◽  
Vol 31 ◽  
pp. 177-179
Author(s):  
W. W. Shane
Keyword(s):  
Preliminary Report ◽  
Progress Report ◽  
Galactic Centre ◽  
Low Latitude ◽  
The Third ◽  
Introductory Lecture ◽  
Centre Region

In the course of several 21-cm observing programmes being carried out by the Leiden Observatory with the 25-meter telescope at Dwingeloo, a fairly complete, though inhomogeneous, survey of the regionl11= 0° to 66° at low galactic latitudes is becoming available. The essential data on this survey are presented in Table 1. Oort (1967) has given a preliminary report on the first and third investigations. The third is discussed briefly by Kerr in his introductory lecture on the galactic centre region (Paper 42). Burton (1966) has published provisional results of the fifth investigation, and I have discussed the sixth in Paper 19. All of the observations listed in the table have been completed, but we plan to extend investigation 3 to a much finer grid of positions.

Interstellar gas in the central region of the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr
Keyword(s):  
Central Region ◽  
Galactic Plane ◽  
Neutral Hydrogen ◽  
Continuum Emission ◽  
Galactic Centre ◽  
Interstellar Gas ◽  
Hydrogen Recombination ◽  
The Galaxy ◽  
Centre Region ◽  
The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

Observations of the continuum near the galactic centre

1967 ◽  
Vol 31 ◽  
pp. 405
Author(s):  
F. J. Kerr
Keyword(s):  
Galactic Centre ◽  
The Past ◽  
Centre Region ◽  
The Continuum

A continuum survey of the galactic-centre region has been carried out at Parkes at 20 cm wavelength over the areal11= 355° to 5°,b11= -3° to +3° (Kerr and Sinclair 1966, 1967). This is a larger region than has been covered in such surveys in the past. The observations were done as declination scans.

Preliminary Report of the Peabody Museum Awatovi Expedition of 1937

1939 ◽  
Vol 5 (2) ◽  
pp. 103-114 ◽  
Author(s):  
J. O. Brew
Keyword(s):  
United States ◽  
Preliminary Report ◽  
The United States ◽  
Primary Objective ◽  
United States Department ◽  
States Department ◽  
The Third ◽  
Peabody Museum

The third Peabody Museum Awatovi expedition, under the direction of the writer began work on July 12, 1937, and remained in the field until November 5, 1937. The explorations and excavations were carried on under permission of the United States Department of the Interior. The continuation of these studies was made possible by the contributions of Mr. and Mrs. William H. Claflin, Jr., Mr. Henry S. Morgan, Mr. and Mrs. Philip Allen, Mr. and Mrs. Raymond Emerson, and the Peabody Museum. Its primary objective was the securing of information relative to the post-Spanish period of Awatovi.

scholarly journals A new distance to the Brick, the dense molecular cloud G0.253+0.016

2021 ◽  
Vol 502 (1) ◽  
pp. 1246-1252
Author(s):  
M Zoccali ◽  
E Valenti ◽  
F Surot ◽  
O A Gonzalez ◽  
A Renzini ◽  
...  
Keyword(s):  
Star Formation ◽  
Molecular Cloud ◽  
Near Infrared ◽  
Formation Rate ◽  
Dynamical Evolution ◽  
Galactic Centre ◽  
The Galaxy ◽  
Centre Region ◽  
Order Of Magnitude ◽  
Red Clump

ABSTRACT We analyse the near-infrared colour–magnitude diagram of a field including the giant molecular cloud G0.253+0.016 (a.k.a. The Brick) observed at high spatial resolution, with HAWK-I@VLT. The distribution of red clump stars in a line of sight crossing the cloud, compared with that in a direction just beside it, and not crossing it, allow us to measure the distance of the cloud from the Sun to be 7.20, with a statistical uncertainty of ±0.16 and a systematic error of ±0.20 kpc. This is significantly closer than what is generally assumed, i.e. that the cloud belongs to the near side of the central molecular zone, at 60 pc from the Galactic centre. This assumption was based on dynamical models of the central molecular zone, observationally constrained uniquely by the radial velocity of this and other clouds. Determining the true position of the Brick cloud is relevant because this is the densest cloud of the Galaxy not showing any ongoing star formation. This puts the cloud off by one order of magnitude from the Kennicutt–Schmidt relation between the density of the dense gas and the star formation rate. Several explanations have been proposed for this absence of star formation, most of them based on the dynamical evolution of this and other clouds, within the Galactic centre region. Our result emphasizes the need to include constraints coming from stellar observations in the interpretation of our Galaxy’s central molecular zone.

scholarly journals Symmetrical Structures in the Galactic Centre Region

1989 ◽  
Vol 136 ◽  
pp. 237-242
Author(s):  
J. H. Seiradakis ◽  
W. Reich ◽  
Y. Sofue
Keyword(s):  
Scientific Community ◽  
Galactic Centre ◽  
Centre Region

Symmetrical structures do exist, in the Galactic Centre region, In this article we attempt to summarize their properties and draw the attention of the scientific community to the advantages of taking them into account when working with models of the Centre of our Galaxy, Our work is corroborated by two new maps of the region at 10.7 GHz.

scholarly journals Transverse kinematics of the Galactic bar-bulge from VVV and Gaia

2019 ◽  
Vol 487 (4) ◽  
pp. 5188-5208 ◽  
Author(s):  
Jason L Sanders ◽  
Leigh Smith ◽  
N Wyn Evans ◽  
Philip Lucas
Keyword(s):  
Near Infrared ◽  
Transverse Velocity ◽  
Absolute Calibration ◽  
Galactic Centre ◽  
Proper Motions ◽  
Low Latitude ◽  
Magnitude Distribution ◽  
Double Peaks ◽  
Public Survey ◽  
Survey Results

ABSTRACT We analyse the kinematics of the Galactic bar-bulge using proper motions from the ESO public survey Vista Variables in the Via Lactea (VVV) and the second Gaia data release. Gaia has provided some of the first absolute proper motions within the bulge and the near-infrared VVV multi-epoch catalogue complements Gaia in highly extincted low-latitude regions. We discuss the relative-to-absolute calibration of the VVV proper motions using Gaia. Along lines of sight spanning $-10\lt \ell /\, \mathrm{deg}\lt 10$ and $-10\lt b/\, \mathrm{deg}\lt 5$, we probabilistically model the density and velocity distributions as a function of distance of ∼45 million stars. The transverse velocities confirm the rotation signature of the bar seen in spectroscopic surveys. The differential rotation between the double peaks of the magnitude distribution confirms the X-shaped nature of the bar-bulge. Both transverse velocity components increase smoothly along the near side of the bar towards the Galactic Centre, peak at the Galactic Centre, and decline on the far side. The anisotropy is σℓ/σb ≈ 1.1–1.3 within the bulk of the bar, reducing to 0.9–1.1 when rotational broadening is accounted for, and exhibits a clear X-shaped signature. The vertex deviation in ℓ and b is significant |ρℓb| ≲ 0.2, greater on the near side of the bar and produces a quadrupole signature across the bulge indicating approximate radial alignment. We have re-constructed the 3D kinematics from the assumption of triaxiality, finding good agreement with spectroscopic survey results. In the co-rotating frame, we find evidence of bar-supporting x1 orbits and tangential bias in the in-plane dispersion field.

scholarly journals The Distance and Orientation of the Galactic Bulge from Mira Variables: A Preliminary Report

1999 ◽  
Vol 192 ◽  
pp. 89-94 ◽  
Author(s):  
R. M. Catchpole ◽  
P. A. Whitelock ◽  
M. W. Feast ◽  
S.M.G. Hughes ◽  
C. Alard ◽  
...  
Keyword(s):  
Preliminary Report ◽  
Near Infrared ◽  
Major Axis ◽  
Galactic Centre ◽  
Spherically Symmetric ◽  
Axis Ratio ◽  
Circular Symmetry ◽  
Mira Variables ◽  
Axis Of Rotation ◽  
Scale Length

Near-infrared, JHKL, observations of 595 Mira variables in two fields on either side of the centre of our Galaxy, confirm that the Bulge is not spherically symmetric about its axis of rotation, but is elongated so that the part to the east of the centre is closer to us. The shape of the Bulge about its axis of rotation is not uniquely defined by these data, but the shape that deviates least from circular symmetry has an axis ratio xo/yo = 1.7, with a major axis at an angle, θ = 58° ± 7, to the plane of the sky, for a galactic centre distance, R0 = 9.4 ± 0.5 kpc. This is based on an assumed scale length in galactic coordinates of bo = 375 pc and lo/bo = 2.0.

scholarly journals Dynamics of OH/IR Stars in the Inner Galactic Bulge

1993 ◽  
Vol 153 ◽  
pp. 341-342
Author(s):  
Anders Winnberg ◽  
Michael Lindqvist ◽  
Harm J. Habing
Keyword(s):  
Mass Distribution ◽  
Gravitational Potential ◽  
Progress Report ◽  
Dynamical Model ◽  
Galactic Centre ◽  
Galactic Bulge ◽  
Ir Stars

Using the VLA at 1612 MHz Lindqvist et al. (1992a) have found 134 OH/IR stars close to the Galactic Centre (GC). These stars plus 15 from Habing et al. (1983) have been used as probes of the gravitational potential to derive the mass distribution in the inner galactic bulge between ≈ 5 to ≈ 100 pc from the GC (Lindqvist et al., 1992b). In this paper we present a progress report of a dynamical model which we have applied to the data.

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